There has been for a long time a need for a device to control precisely cooking of comestibles and deep fat fryers precisely and easily. A number of approaches have been developed in the prior art.
U.S. Pat. No. 3,979,056 to Barnes for a Multi-Product Cooking Computer discloses an electronic circuit having a timer controlled in part by a temperature probe submerged within heated oil or shortening in a deep fat fryer well. The temperature probe controls the rate of oscillation of an oscillator 22. Oscillator 22 drives a counter 24. When counter 24 counts a predetermined number of oscillations of oscillator 22, an output signal is provided indicating that cooking has been completed. In other words, Barnes employs a temperature adjusted oscillator to perform a type of time-temperature cooking integration. Barnes also provides a plurality of product selection switches which connect different resistances in series with a capacitor 68 to control the period of the oscillator. However, should it become necessary to adjust the time for which a particular product selection switch conditions the oscillator internal adjustments of a mechanical or electronic nature would have to be made to the circuit.
Another approach was taken in U.S. Pat. No. 4,197,581 to Watrous et al, for a Control System for and Method of Controlling a Cooking Appliance. Watrous teaches the use of a combination microcomputer controller having associated circuitry for controlling a deep fat fryer. Watrous, preloads timing counters from diode matrices. Watrous, like Barnes, employs a temperature variable frequency oscillator but uses it to actuate microcomputer counters. The variable frequency oscillator of Watrous is controlled by a cooking control probe R801 so that as the probe, which is submerged in heated oil, becomes warmer, the oscillator runs faster. There is no provision in Watrous for altering the preload cooking counter without rewiring a circuit board.
There appears to be no prior art on a precise apparatus and method for controlling a deep fat fryer and having the facility for reprogramming. The reprogramming facility should be usable by persons in authority without the problems associated with tampering of controlled information by unauthorized persons.